Coated fabric and method of making the same



Oct. 26, 1937. H. L. MUNROE 89 COATED FABRIC AND METHOD OF MAKING THE SAME Filed July 8, 1936 7 Jfibwaa d Z. Munroe,

flfijjys Patented Oct. 26,1937

UNITED STATES PATENT OFFICE COATED FABRIC AND METHOD OF MAKIN T E SAME 4 Claims.

This invention relates to a leather-like coated fabric and the method of making the same. It contemplates a product comprising a textile fabric base or strain-resisting, flexible backing bound or united to a facing layer of comminuted cork applied in such manner that a fabric is produced of light weight, substantial body, water and heat resisting properties, great flexibility and tensile strength and with a surface finish such that it is applicable to a wide variety of uses.

This application is a continuation in part of my prior co-pending application, Serial No. 69l,013,'filed September 26, 1933.

A cork coated fabric of the type hereinafter described may be employed, among other uses, as a vamp lining for shoes, for innersoles, as a substitute'for leather in the manufacture of artificial leather and particularly imitation patent leather, either by the customary hand japanning process or by a pyroxylin coating, and for numerous other purposes where lightness, body, flexibility and water resisting properties are desirable.

The invention will be best understood by reference to the following description of one or more specific embodiments thereof when taken in connection with the accompanying illustration, while its scope will be more particularly pointed out in the appendedclaims.

In the drawing:

Fig. 1 is a representation of the cork coated face of a fabric embodying one form of the invention;

Fig. 2 is a cross-sectional elevation, on a greatly exaggerated scale, of the fabric shown in Fig- 1;

Fig. 3 is a similar cross-sectional elevation showing the addition of a coating to provide an imitation patent leather;

Fig. 4 is a diagrammatic representation of a coatingand drying machine which may be employed in carrying out the process; and

Fig. 5 is a diagrammatic representation of an apparatus employed for surfacing the cork.

The physical characteristics of the cork coated fabric may be best explained in connection with a description of one method employed in producing it.

The textile fabric for the base or backingof the product is selected according to the use to which the coated fabric is to be applied. For

' example, in the case of its, use for shoe vamp linings, a white twill-weave cotton fabric may be employed, the weight of which, by way of example, may be one-half pound to the yard. If the coated fabric is intended to be used for imitation patent leather, to secure added flexibility a more finely finished and somewhat lighter weight of cottontwill may be employed, such as that known as sateen weave, this being dyed to a color corresponding to the patent leather flnish,- 5 brown, for example, if a brown finish is to be applied, or black if a black finish is used.

The selected textile fabric, in the form of a continuous strip, has applied to one side thereof a plastic coating composed ofa cellulose ester 10 binding solution which, for example, may consist of pyroxylin or cellulose acetate. On this there is then'spread or distributed a quantity of comminuted or granular cork, the latter being caused to adhere to the coated side of the textile fabric. 15 The cork coated fabric then passes through a drying device, after which it is wound on a roll preparatory for the next operation.

An apparatus of the type diagrammatically shown in Fig. 4 may be employed for the coating 20 and drying operation. This comprises the supply roll II on which the fabric I3 is wound, the latter being then fed over guide rollers and under tension onto the coating table 15 where the plastic .solution is applied to and spread across its sur- 25 face. The solution may be applied by hand or fed under suitable regulation from a supply chamber H. The fabric is then fed beneath the doctor blade I9, passing thence, whilest'ill wet and sticky from the plastic coating, into' the cork 30 box 2| which is kept fllled with finely granulated cork. The fabric strip passes down through the mass of cork and thence upward and out of the same, accumulating on its coated tacky surface a covering of the granulated cork particles. The 35 loose particles of cork are removed from the under-surface of the fabric as it emerges from the cork box by a.rotary brush 23. From the cork box the fabric passes into and through a drying chamber 25 over guide rollers 21, describing looped paths between which are positioned steam drying pipes 29. The drying of the fabric may be further accelerated by the introduction into the drying room of hot air through the hot air pipes 3|. The dried fabric on emerging from the drying room is wound up on the winding.- roll 33.

If a pyroxylin solution is employed, this may be composed of nitro cellulose and a suitable 50 solvent, with a small quantity of castor oil to give flexibility to the fabric. As an example of the solvent, it may comprise 25% of ethyl acetate. 25% of alcohol,- and 50% of benzol, 24 ounces of nitrocellulose being added to each gal- 55 the innermost corkgranuiles being firmly united worked upon.,

The cork coated fabric is subsequently subjection of the solvent and mixed into the form of a j ly.

As an example of cellulose acetate, if that be employed, the solvent may comprise 30% chemically pure acetone, 30% ethyl acetone, 20% methyl cellosolve (ethylene glycol monoethyl ether) and 20% of a plasticizer, such, for example, as that commonly known as M 1'1. To each gallon of solution there is added 32 ounces of cellulose acetate which is mixed into the 'form of a jelly. i r

The process is herein described as carried out through the use of pyroxylin but may be performed by the same steps when other cellulose ester solutions are made use of, as, forexample, (cellulose acetate.

The solution should be sufficiently thick and viscous to cause the ready. adherence of the cork to the coated surface to provide a bond and anchorage for the cork coating and to bind and blend with the innermost cork granules when the fabric is subjected to the compression hereinafter described. The solution, however, should be sumciently fluid to penetrate the fibers on the face of the textile fabric to be coated, but preferably without marked tendency to strike through the fabric and mar the original clean appearance of the uncoated face of the latter by evidences thereon either of the solution or the cork particles. This desired condition is promoted byslight- 1y starching the fabric before being coated, to

size the same.

I have found that any evidence of the discolor-' ation referred to may be avoided by first sizing the fabric with a coating of pyroxylin solution and drying the same, as by such means as are' indicated in Fig; '4, but without the intermediate step of applying the cork to the coated surface. The fabric, thus preliminarily coated with pyroxylin, if that be the case, is then passed through the operation just previously described,

and in the apparatus represented-in Fig. 4, that is to say, by applying a second coat of pyroxylin to the previously coated surface, followed by the addition thereto of the corkand the drying operation. This preliminary coating step I prefer to employ in connection with products where such discoloration may be a disadvantage. It may also be advantageously used for the purpose of imparting a body to the underlying fabric backin which is important in certain applications, such, for example, as where the product is used for vamp linings for shoes. J

The cork coated fabric as it emerges from the drying room presents a rough, granular surface.

to the face of the textile fabric and the outermost particles less firmly united. Loose particles of cork may beremoved from the surface, by-subsequently subjecting the fabric to the action of a suitable brushing machine before it is further ed to operations serving to impart solidity, firmness,.and a finished surface to the cork.

For certain products asingle coating of the cork .will suflice. Preferably, however, to give the desired body to the cork covering, the'fabric through the coating machine,thereby superimposing on the face of the original cork coating another coating of pyroxylin, and on the top of. the pyroxylin a second layer of granular cork, which latter becomes set and bonded to the under layers by the drying operation.

The fabric with the double layers of cork bound thereto is then subjected to a solidifying and firming action. A simple method of securing the desired result is to feed the double coated fabric be-' tween steam heated calendering rolls heated to a temperature just sufficient to very slightly soften the pyroxylin without disturbing the bond and adjusted to exert a substantial compression upon the coated fabric as it passes between them. Or, in place of heated calendering rolls, a fric-; tion calender may be used so adjusted as to gencrate a suflicient amount of heat to soften the;-

between the particles or granules and the fibers thereof, thereby binding the cork particles into a more compact condition which they permanently retain. This imparts a relatively greater solidity, strength and permanency to the coating, the

cork particles, and more particularly those in close proximity to the pyroxylin, being blended, as it were, into the pyroxylin binder. The calendering operation also imparts a smooth, even surface to 'the'cork on the coated side of the fabric.

A calendering operation similar to the one described, to which the fabric is subjected after the application of .the' second coating of cork, may in many instances, depending on the use to which the product is to be put, be advantageously applied to the fabric after the application of the first coating of cork and before the application of the second cork coating. Such intermediate calendering tends further to compact the cork and improve; its bond as well as the surface thereof.

The fabric with its solidified coating produced by any of the steps hereinbefore described and its calendered'surface may then be subjected to a smoothing operation designed to remove any unevenness in the surface of the -cork face due to irregularities in the distribution or thickness of the cork, or to other causes, and designed further to provide a soft, surface finish by raising a fine nap on the face of the cork, which finish closely resembles the finish of suede leather in appearance and feel.

This operation may be performed by subject- 7 ing the cork faced the fabric to the carefully controlled and regulated abrading or bufilng operation of the apparatus which is diagrammatically represented in Fig. 5. In this apparatus the fabric l3, with the-coated face downward, is

fed. under tension over the plate 35, beneath the feed rollers 31 and between the buffing cylinder 38 and the'guidingroll 4|, the latter beingsusceptible of very fine adjustment ina vertical direction to secure a close, exact regulation of the space between .thesurface of the bufllngcylg The bufling cylinder index and the guide roll. is suitably surfaced, as'with fine'sand paper 'or other abrading or buffing material, and is also so constructed that, besides being rotated at 9."

- high rate of speed, it has imparted to it a re-' ciprocating axial movement, this insuring anevenly distributed bufiing action over he .cork

surface without the production of scratches or other marring efi'ects.

The buffing action carried out in the manner described produces a soft surface on the cork,- characterized by the seemingly napped appearance of the cork face interspersed with occasional minute pores, closely resembling the surface appearance of suede leather.

The finished appearance of the fabric made by the use of the two cork coatings as described is illustrated in Figs. 1 and 2. Referring to Fig.2, where an attempt has been made'to represent a cross-section of the fabric on a greatly exaggerated scale, the textile backing is indicated at 43, this being firmly bonded to the adjacent py- The first or inner cork roxylin coating at 45. layer is represented at 41, the outer or surface cork layerv at '49, and theintervening pyroxylin at 5|. The inner cork layer 41 becomes more or less blended withthe underlying pyroxylin 45 and the overlying pyroxylin 5|, and the bottom of the outer cork layer becomes similarly more i or less blended with the pyroxylin coating 5|.

. cork surface a facing of pyroxylin 53 imparting The surface of the outer'cork layer or coating will be free from any appearance of the pyroxylin, the

cork layer thus completely covering and concealing the underlying cellulose ester binder.

The fabric thus produced has a substantial body or thickness for a given weight, this characteristic making it particularly available for the vamp lining of a shoe, since a single piece vamp lining cut from thisfabric may be em-' ployed insubstitution for the several pieces of fabric commonly required for that purpose and which comprise the fabric lining itself, a doubler to give body to the lining, and in many cases a;

The

rubberized backingcloth for'the leather. fabric'herein described is also waterproof or water-resisting, heat insulating, of substantial tensile strength, capable of being stitched, and of a flexibility approximating that of the textile fabric forming the base or backing and substantially "equal to that of leather of the same thickness.-

These qualities make itiavailable for a wide variety of uses. 'One use which may be referred to is as a base for imitation patentleather. An example of this is shown in Fig. 3,,where the corkcoated fabric substantially similar to that previously described has had applied to the outer to it a patent leather finish.

In the manufacture of the imitation patent leather, and in some cases in the manufacture of the fabric for other purposes, it may be desirable to reverse the order of the bumng and coating to which the outer pyroxylin coating for.

the calendering operations, the cork coated fabric being first buffed and then calendered instead of being first calendered and then buffed. In the case of imitation patent leather this provides a smooth, even surface for the finally finished cork the patent leather may be applied with better effect and appearance.

The pyroxylin facing 53 maybe built up by passing the cork coated fabric through acoating machine and applying the pyroxylin to the cork coated surface in the usual manner, drying the coating and repeating the operation a sufficient number of times to get the necessary depth and finish to the facing, the pyroxylin solution applied in the successive coats being varied in respect to thinness to secure the necessary glossy surface finish. The-pyroxylin solution, with'tl'i'e addition of a pigment giving the necessary color,

may be made up of nitro-cellulose, with a sufflcient solvent of the character previously described, preferably using also a small quantit of castor .oil mixed with the solution.

Due to the peculiar characteristics of the cork coated fabric, it may be successfully and practically employed as a body for the production of imitation patent leather, produced by the japanning process instead of the machinecoating method last described. That process, as is well known, is carried out by manually applying to the leather,or in this case the cork coated fabric,--by brushing or rubbing into the surface thereof. a succession of coats comprising principally linseed oil mixed with a suitable pigment,

the'material being dried or baked between sue-' cessive coats.

The cork.coated-fabric makes a particularly useful imitation patent leather, since it provides cracking of the patent leather surface finish.-

The cork coated fabric is particularly useful in the manufacture of imitation grained or embossed leathers. These have been usually made by applying pyroxylin coats directly to the face of a textilefabric and then embossing the coated face ofthe fabric under'heavypressure. In this method it is diflicult to eliminate the evidence of the weave in the cloth except through the use of an excessive number of coatings. The cork coating on the described fabric, presenting a smooth,

uniform surface, offers no such objection and being highly compressible facilitates the production of the embossing design.

It is preferred to dye the comminuted cork prior 25 within the shoe tends to the deterioration and the to its incorporation in the fabric when the product is intended for uses wherein'it would be noticeable and the natural cork color might beconsidered objectionable, for example, when the,

product simulates patent leather.

While I have herein shown for purposes of illustration one specific embodiment of the coated fabric comprising the invention and have described one method by which it may be produced,

extensive deviations may be made in the method of production and in the product, all without departing from the spirit of the invention.

I claim:

1: As a new article of manufacture, a flexible patent leather-like fabric comprising-a sheet of I woven textile material, a sizing'ofcellulose ester selected from the group consisting of cellulose acetate and cellulose nitrate applied directly to the material and having a penetrating anchorage in the body thereof, a like cellulose ester binder overlying said sizing, a layer of comminuted cork completely covering and concealing the binder firmly united thereto and compressed therein, said cork layer having a smooth leather-like surface and 'ayielding base, said fabric further having an outer glossy patent leather-like facing comprising a plurality of coats of nitrocellulose coverflexibility of the original woven textilematerial.

, ing the smooth surface of the cork, the coated 2. The method of making a cork coated fabric to imitate leather while maintaining substantially ester solution selected from the group consisting of cellulose acetate and cellulose nitrate to pro vide a coating having a penetrating anchorage in the fabric base protecting said base against discoloration, drying said protective coating, ap-

plying a coating of like cellulose ester binder directly to said dried protective coating, immediately applying a relatively thick layer of comminuted cork thereto completely covering and concealing said binder before the latter dries. quickly and thoroughly drying said binder under heat, and calendering the fabric after the cork coating andbinder have become dried and set.

3. The method of making a cork coatedfabric to imitate patent leather while maintaining substantially the flexibility of the fabric base which quickly and thoroughly drying said binder under heat, calendering the fabric after the cork coating and binder have become dried and set, and applying a plurality-of coats of patent leatherlike facing to said calendered surface, and thoroughly drying said coats between successiveapplications. 1

4 The method of making a cork coated fabric to imitate leather while maintaining substantially the flexibility of the fabric base which comprises sizing a woven textile fabric base with a cellulose ester solution selected from the group consisting of cellulose acetate and cellulose nitrate to.provide a coating having a penetrating anchorage in the fabric base protecting said base against discoloration, drying said protective coating, ap-

plying a coating of like cellulose ester binder dif rectly to said'dried protective coating, immediately applying a relatively thick layer of comminuted cork thereto completely covering and concealing said binder before the latter dries, quickly andthoroughly drying said binder under' heat, and calendering the fabric after the cork coating and binder have become dried and set. under heat and pressure to slightly soften the. binder and compress the cork layer therein. HOWARD L. MUNROE. 

